Magnetic-core memory construction



United States Patent MAGNETIC-CORE MEMORY CONSTRUCTION Lionel Crown, Santa Monica, Seymour Markowitz, Los

Angeles, and David Slotnick, Sherman Oaks, Califi,

assignors to Ampex Corporation, Culver City, Calif.,

a corporation of California Filed Nov. 6, 1 961, Ser. No. 150,257 3 Claims. (Cl. 340-174) This invention relates to magnetic-core memory construction and, more particularly, to an improvement therein.

The presently favored manner of constructing a multiplane-type of magnetic-core memory is tofabricate a plurality of separate core planes each having its own supporting frame, mount the separate frames in a suitable supporting rack, and then wire these frames together and to external driving equipment. Each core plane comprises a plurality of toroidal magnetic cores, disposed in rows and columns. Driving windings, as well as sensing and inhibiting windings, are threaded through the rows and columns of cores and are brought out to suitable terminals which are provided on the frames. The frames are used to support the cores in a digit plane. Since there are a plurality of rows and columns of cores, the termination of the drive windings for each of these rows and columns requires a considerable number of solder connections to be made on the frame for the digit plane. A considerable number of connections must again'be made in wires which link the plurality of digit planes together, so that the memory may be operated as an integrated system.

An object of this invention is to simplify the construction of a magnetic-core memory of the type comprising a plurality of digit planes.

Another object of the present invention is the provision of a method and means for reducing the number of connections required in the fabrication of the magnetic-core memory, consisting of a plurality of digit planes.

Still another object of the present invention is the provision of a simple and useful method and means for fabricating a magnetic-core memory.

These and other objects of this invention may be achieved in an arrangement wherein the rows and columns of cores for each digit plane are placed side by side on a suitable support. The driving windings for the entire memory can then be threaded through the columns and rows of cores in each digit plane, without the necessity for soldering these drive windings on the respective frames for each digit plane. After the threading of the various core planes by the operating windings has been completed, the spread-out core planes may be compacted by folding the entire arrangement in the manner of an accordion, so that the space occupied by the plurality of core planes effectively is not much more than the sum of the thicknesses of all of the core planes.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the followingdescription when read in connection with the accompanying drawings, in which:

FIGURE 1 shows an arrangement for holding a plurality of cores in a core plane;

FIGURE 2 shows the disposition of the core planes during the threading operation;

FIGURE 3 shows the core planes being folded together; and

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FIGURE 4 shows a compact memory which has been fabricated in accordance with this invention.

A well-known method of assembling magnetic cores and holding them in position while they are being threaded is to use an apertured plate wherein each aperture has dimensions suflicient to enable a magnetic core to fit partially therein and extend above the plate. These apertures are arranged over the plate at the same angles as it is desired for the magnetic cores to assume when finally wired. In FIGURE 1, there is shown such an aperture plate 10 with the plurality of apertures 12 into which there has been inserted magnetic cores 14, which extend above the surface of the plate. Usually, the aperture plate is made the bottom of a box with removable walls. A plurality of the cores are dumped into the box, suction is applied to the outside of the apertured plate, and the box is vibrated until a core has been captured in each one of the apertures therein. The walls are then removed.

A suitable adhesive tape 16 is then pressed against those portions of the magnetic cores which extend above the apertured plate. Then, when the adhesive tape is removed from the plate, the magnetic cores adhere thereto. A suitable plastic is sprayed over the cores, to insure their adherence to the adhesive tape in a manner so that they effectively are stood up on one end with the orientation given by the arrangement of the apertures in the apertured plate. This plastic is subsequently dissolved away.

As thus far described, the method for standing the magnetic cores on edge in a desired configuration is known and is not considered as a part of this invention. FIG- URE 2 shows the disposition of a plurality of the arrays of magnetic cores which have been processed in the manner just described. Only four arrays are shown, respectively 22, 24, 26, 28. These are representative of as many arrays as are desired or required to fabricate all the digit core planes of a magnetic-core memory. Each one of these arrays, consisting of a plurality of magnetic cores which are held standing on edge by the tape 16, are placed on a table or jig 30, spaced from one another and oriented diagonally relative to one another. The magnetic cores may be held in position on the table by attaching the corners of the adhesive tape to pins 29 extending from the plane surface 30. Any other suitable arrangement may be employed for spacing and aligning the sections of adhesive tape to which the magnetic cores adhere. The space between the sections of adhesive tape is effectively determined by the sizes of the frames 32, 34, 36, 38, which will support the magnetic cores which will constitute each digit plane.

If each array of rows and columns of cores is considered as defining a rectangle, then these rectangles are placed relative to one another, so that one of their two diagonals is always parallel with the other. After each section of adhesive tape is placed on the table surface, a separate frame or core plane support, respectively 32, 34, 36, 38, is positioned over each tape section holding a plurality of cores. Each one of these core frames constitutes a rectangle, preferably made of thin plastic material and having a central rectangular aperture, respectively 32A, 34A, 36A, 38A, which, as shown, is disposed diagonally relative to the rectangular outer dimensions of the frame. The size of these inner apertures is large enough to clear the array of magnetic cores which it is intendedto support.

Each frame has other apertures disposed thereon. These will be described in detail for the frame 34. Since the other frames are identical, a description of the detailed apertures in frame 34 should sufiice here. At each corner of the frame 34 are apertures, respectively 40, 42, 44, 46. These apertures are provided for the purpose of enabling bolts, which will support the entire memory, to be passed therethrough.

Slot-like apertures, respectively 48, 5d, 52, 54, are parallel to the edges of the frame, but are disposed on both sides of the central opening 34A. The. purpose of these slot-like apertures is to enable the passage therethrough of the wires from the preceding core plane to the succeeding core plane. Each core frame has two terminals, respectively 56, 58, which are at one side of the core frame, and the inhibit winding for a core plane is connected to these two terminals. Terminals 68, 62 are on the other side of the core frame, and a reading winding connects these two. There is also provided on each core frame a plurality of apertures 64. One of these apertures is provided and positioned on each side of the central aperture, at which a row of cores will be located. Similarly, there is another one of these apertures on each side of the central aperture, at which a column of cores will be located.

A coincidence current memory has a drive winding passing through all the cores in a row and another drive winding passing through all the cores in a column. As is well known, the core selected to be driven is the one which is coupled to an excited column winding and row winding. In accordance with this invention, the threading of the row and column drive windings through the entire memory is continuous and uninterrupted at each core plane, which has not been the practice heretofore. Thus, a row winding 66 first passes up through one of the small holes 64, which is adjacent the row of cores through which this winding is to be threaded, the winding then threads through the row of cores, then down through the hole 64 at the other side of this row. The winding 66 then passes up through the slot 54, then down through the slot 50 in the adjacent core frame 34. The winding 66 then passes up through the small hole 64 adjacent the row of cores through which it is to pass in the second plane. The winding 66 then passes down through the small opening 64. The winding 66 then passes up through the slot 52 across and down through the slot 48, which is in the core frame 36. The winding 66 then passes up through i the hole 64 through the first row of cores in the third core array. It then passes down through the corresponding hole 64, and up through the corresponding slot 54 in the frame 36. The winding 66 thus is continuously threaded in the manner described through the sub stantially correspondingly located row of cores in each core array of the different core planes and through the apertures in the core planes. This pattern is carried out for the entire memory.

For the columns of cores in the various core planes, the continuous threading through all core planes is followed as for the rows of the cores. A winding 63 is passed through a column of cores in the first core plane. It is then passed through theraperture 64, which is posit1oned in the core frame portion adjacent that column of cores. The winding 68 is then passed through the slot 52 in the frame 32. It comes up through that slot and over, down through the adjacent slot 48 in the frame 34. The winding then passes up through the aperture adjacent the correspondingly positioned column of cores in the second core array. This pattern of successively passmg a winding through the small apertures adjacent a row or column of cores is for the purpose of properly aligning and positioning the winding and keeping it spaced apart from the other windings required.

It should be appreciated from the preceding description how the driving windings which pass through the rows and columns of cores are not terminated on each core plane, but, rather, are continuously threaded through the various rows and columns of the entire memory. Another feature of this invention, which is obtained as a result of the diagonal placing of the various core arrays, is that the wire of the windings Which extends between adjacent arrays is perfectly straight, the only slight bend in these wires occurring either before or after a column or row at an aperture 64. This is achieved by threading a drive winding through a row of cores in one core plane which extends from below to above the nonparallel diagonal of that core plane, and then threading the winding through a row of cores in the succeeding core plane, in reverse, or from above to below the nonparallel diagonal of the succeeding core plane. This alternate direction of threading the row windings is carried out through the whole memory. The column windings follow the same pattern of altering the direction of threading through the columns of cores. This straightens the wire between core planes.

An inhibit winding 70, 72, 74 is provided for each core plane. These are vestigially shown. The inhibit winding is a winding which passes through every single one of the cores in a particular core plane for the purpose of inhibiting the drive applied to a core of that plane in the process of writing. The reason for showing this winding vestigially is that to do otherwise would complicate the drawing without adding to the clarity thereof. A reading winding 76, 78, 80, 84 is provided for each core plane. This, too, is only vestigially indicated. As is known, the reading winding comprises a winding which is inductively coupled to each core in a core plane. The inhibit windings are terminated at the respective core planes on the respective terminals 56, 58, 57, 59, 61, 63. The reading, or sensing, winding for each one of the core planes is connected to the respective terminals 65, 67, 6t 62, 69, 71, 73, and 75.

The importance of having the wires straight between the core planes may be seen by referring to FIGURES 3 and 4. After all the row and column windings and all the respective reading and inhibit windings have been threaded through the cores, the cores are removed from the adhesive tape by spraying them with a solution which dissolves the plastic and the adhesive therefrom. The cores are supported now by the windings passing through the apertures and slots of the core planes. The core planes may then be folded accordion fashion, as shown in FIGURE 3, to be collapsed into a compact memory, as shown in FIGURE 4. A terminal strip is placed adjacent the slots in the end core plane, through which the row and column windings, respectively 66 and 68, extend. The row and column winding terminations can then be made by soldering the end of each winding to one of the terminals on the terminal strip 80. Bolts 84, 86, 88, are used to rigidly hold the core planes in the closed position to which they are collapsed and to also support the terminal strips 80, which are on either end of the entire memory. These bolts are passed through the apertures 40, 42, 44, 46, which are provided at the corners of each one of the core frames.

It will be seen that the arrangement of the cores in the core frames has the virtue of isolation of the terminals of the various windings in that the inhibit-winding terminals for the various core planes are available at one side of the core frames, and the sensing winding terminals are available on the opposite side of the core frames. The row and column drive windings are available at the remaining sides. Another advantage of the arrangement provided herein is that, if desired, a testing of the complete memory may be made before the memory is collapsed or folded into its compact form and while it is still laid out in its flat form. The advantage of this is that should there be any defect in the memory, it can be readily traced and corrected while the memory is still in the open form, which is more difficult to do with other memories which are assembled compactly. By arranging 70 to have the wires between the memory planes straight,

to the driving wires is minimal.

55 FIGURE 2, or their relative disposition, so that diagonals extending through two vertices of the arrays are parallel.

It is within the scope of this invention to omit any of the apertures in the frames, such as the apertures 64, whereby the drive windings thread through the remaining apertures in the frames. Also, it is within the scope of this invention to thread the core planes with wire and to omit the frames. The entire memory, after being folded into a compact form, is dipped in plastic, which is in liquid form and which, upon hardening, holds the memory together and protects it. Of course, the ends of the drive, inhibit, and sense windings are protected and extend from the enveloping plastic to be available for connection to the associated operating apparatus.

There has accordingly been shown and described herein a novel, useful, and simple method and means for fabricating a magnetic-core memory. This invention eliminates a plurality of solder joints heretofore required for magnetic-core memories employing a plurality of core planes. This lends reliability to the memory, since the elimination of solder joints minimizes the possibilities of poor connections which often cause problems. With the arrangement of the memory shown, a single bend is given to the drive wires, to enable the compaction of the memory. The memory provides volumetric efficiency by reason of the elimination of hardware, such as terminals, on each core frame. This hardware would prevent the various core planes from being positioned as closely together as possible. Testing and repair are also made simpler, since, in the event a difficulty is experienced with a particular row or column in a core plane being tested while still in the form as shown in FIGURE 2, it is a simple matter to cut an entire row or column of cores from out of the core plane and solder a new row or column of cores therein.

We claim:

1. An improved structure for a magnetic-core memory comprising a plurality of rectangular arrays of cores, each array including cores disposed in columns and rows, a rectangular frame for each array, each said rectangular frame having a rectangular opening positioned with its two diagonals parallel to two adjacent sides of said rectangular frame, said opening being large enough to receive a core array and within which a core array is positioned, each said frame having a rectangular opening adjacent each of the sides of the opening for a core array, a separate row winding for each different row of cores in all of the magnetic-core arrays, a separate column winding for each different column of cores in all of the magnetic-core arrays, each said row winding constituting a wire which threads uninterruptedly and without any intervening terminations through the openings in each frame adjacent the rows of cores and through each row of cores which is correspondingly located in each of the core arrays, each said column winding constituting a wire which threads uninterruptedly and without any intervening terminations through the openings in each frame adjacent the columns of cores and through each column of cores which is correspondingly located in each of the core arrays, the direction of threading of each row-winding wire through each row of cores being reversed on each succeeding core plane, the direction of the threading of each column-winding wire through each column of cores being reversed on each succeeding core plane, both said row winding and column winding wires extending parallel to one another from one side of a core plane to an adjacent side of an adjacent core plane.

2. An improved structure for a magnetic-core memory as recited in claim 1 wherein said frames and the included array of cores are disposed parallel to one another, means for holding said frames in said parallel position, and terminals mounted on the outside frames to which the ends of said plurality of columnand row-winding wires are connected.

3. An improved memory as recited in claim 1 wherein each said frame has substantially rectangular outside dimensions and wherein said opening in each frame wherein an array of cores is inserted is rectangularly and diagonally disposed relative to the rectangular outside dimensions, and wherein the openings in each said frame adjacent each of the sides of the opening for a core array constitutes four slots two of which are aligned and parallel to an edge at one side of a frame, the remaining two of said slots being aligned and parallel with an edge at an opposite side of a frame.

References Cited in the file of this patent UNITED STATES PATENTS 2,910,673 Bloch Oct. 27, 1959 2,934,748 Steiman Apr. 26, 1960 2,961,745 Smith Nov. 29, 1960 2,975,406 Stallard Mar. 14, 1961 2,985,948 Peters May 30, 1961 FOREIGN PATENTS 533,077 Italy Sept. 16, 19 

1. AN IMPROVED STRUCTURE FOR A MAGNETIC-CORE MEMORY COMPRISING A PLURALITY OF RECTANGULAR ARRAYS OF CORES, EACH ARRAY INCLUDING CORES DISPOSED IN COLUMNS AND ROWS, A RECTANGULAR FRAME FOR EACH ARRAY, EACH SAID RECTANGULAR FRAME HAVING A RECTANGULAR OPENING POSITIONED WITH ITS TWO DIAGONALS PARALLEL TO TWO ADJACENT SIDES OF SAID RECTANGULAR FRAME, SAID OPENING BEING LARGE ENOUGH TO RECEIVE A CORE ARRAY AND WITHIN WHICH A CORE ARRAY IS POSITIONED, EACH OF SAID FRAME HAVING A RECTANGULAR OPENING ADJACENT EACH OF THE SIDES OF THE OPENING FOR A CORE ARRAY, A SEPARATE ROW WINDING FOR EACH DIFFERENT ROW OF CORES IN ALL OF THE MAGNETIC-CORE ARRAYS, A SEPARATE COLUMN WINDING FOR EACH DIFFERENT COLUMN OF CORES IN ALL OF THE MAGNETIC-CORE ARRAYS, EACH SAID ROW WINDING CONSTITUTING A WIRE WHICH THREADS UNINTERRUPTEDLY AND WITHOUT ANY INTERVENING TERMINATIONS THROUGH THE OPENINGS IN EACH FRAME ADJACENT THE ROWS OF CORES AND THROUGH EACH ROW OF CORES WHICH IS CORRESPONDINGLY LOCATED IN EACH OF THE CORE ARRAYS, EACH SAID COLUMN WINDING CONSTITUTING A WIRE WHICH THREADS UNINTERRUPTEDLY AND WITHOUT ANY INTERVENING TERMINATIONS THROUGH THE OPENINGS IN EACH FRAME ADJACENT THE COLUMNS OF CORES AND THROUGH EACH COLUMN OF CORES WHICH IS CORRESPONDINGLY LOCATED IN EACH OF THE CORE ARRAYS, THE DIRECTION OF THREADING OF EACH ROW-WINDING WIRE THROUGH EACH ROW OF CORES BEING REVERSED ON EACH SUCCEEDING CORE PLANE, THE DIRECTION OF THE THREADING OF EACH COLUMN-WINDING WIRE THROUGH EACH COLUMN OF CORES BEING REVERSED ON EACH SUCCEEDING CORE PLANE, BOTH SAID ROW WINDING AND COLUMN WINDING WIRES EXTENDING PARALLEL TO ONE ANOTHER FROM ONE SIDE OF A CORE PLANE TO AN ADJACENT SIDE OF AN ADJACENT CORE PLANE. 